Study Finds Link Between Alzheimer’s, Diabetes

Source: USA TODAY, May 18, 2004
Author: Kathleen Fackelmann

Older men and women with diabetes face a 65% increased risk of developing Alzheimer’s disease, a large, federally funded study reports today.

If confirmed by other reports, the findings suggest that the rates of Alzheimer’s disease might climb even higher than projected in the next few decades, fueled by the nation’s epidemic of obesity. Obesity is a major cause of diabetes. About 4.5 million people have Alzheimer’s, a number that could rise to at least 16 million by 2050.

Other studies have suggested a tie-in between diabetes and Alzheimer’s, but today’s report is the largest yet to show the link.

Researchers at the Rush University Medical Center in Chicago used data from an ongoing aging study involving a large group of Catholic nuns, priests, and brothers who volunteered for the project.

None of the 824 people had any sign of Alzheimer’s at the beginning of the study and 127 had diabetes, a disease in which the body is unable to process sugar properly. The researchers gave the participants a battery of tests each year, and after five years, they found that 151 had developed Alzheimer’s.

A statistical analysis found that people with diabetes had a much higher rate of developing Alzheimer’s disease than those who don’t have diabetes. Age is still the greatest risk factor for developing Alzheimer’s. One in 10 Americans over 65 and nearly half of those over 85 have the incurable, progressive brain disease.

No one knows for sure why diabetes might boost the risk of Alzheimer’s. One theory is that diabetes reduces the amount of fuel, or glucose, that goes to all body cells, including brain cells.

Brain cells might not get enough glucose to work at top speed, and over time Alzheimer’s might develop, says Bill Thies of the Alzheimer’s Association.

Diabetes can affect the brain in other ways too. The study found that diabetics had a 44% greater decline in their ability to quickly size up lists of numbers compared with those without diabetes. Such a performance drop could translate to difficulty balancing a checkbook, says Zoe Arvanitakis, a neurologist at Rush and the lead researcher for the study, which appears in the May Archives of Neurology.

The study included mostly whites, so it is not known whether the link will hold up for blacks or other minorities, says Neil Buckholtz of the National Institute on Aging, which paid for the study. Still, the results are solid and raise an alarm about the nation’s growing problem with obesity, he says.

Americans don’t need to wait for confirmation of the study. Most Americans would benefit by getting more exercise and eating a more healthful diet, Thies says.

“You don’t have to run marathons or live like a monk,” he says. He says even modest changes in diet and exercise can help shave off a few extra pounds, a step that can reduce the risk of diabetes and help ward off Alzheimer’s as well.